Progressive jacks are used to construct segmented structures such as tanks and grain bins. Typically, the construction of a round segmented structure is conducted by first assembling a plurality of curved metal panels into a continuous ring. Usually, at this point a roof is attached to the first ring of panels. Next, the builder will attach a plurality of evenly spaced jacks to the panels. Once the jacks are attached to the panels, the jacks can be operated to lift the first ring of panels to a sufficient height to allow the installation of a second ring of panels under the first ring of panels. The jacks are disconnected from the first ring and connected to the second ring. The lifting and panel installation process continues until the bin is constructed to its planned height. The operation of the lifting jacks is critical to this process. It is important that all the jacks move in unison. Typically, hydraulic jacks, that is, jacks including hydraulic rams are used and a hydraulic distribution system is arranged to supply equal amounts of pressurized hydraulic fluid to the plurality of jacks at generally equal flow rates and pressure so that all of the jacks extend in unison and lift the structure evenly. Staged, telescoping jacks, as taught by applicant's U.S. Pat. Nos. 6,299,137, 6,311,952 and 6,641,115 which are incorporated herein by reference, have been used for over ten years to erect grain bins and other cylindrical tank like structures. The availability of hydraulic jacking systems of the type noted above has led to an expansion of the use of such systems. Further, the availability of such hydraulic jacks has motivated bin material suppliers to offer sets of prefabricated components increasingly larger and heavier structures.
Although telescoping jacks of the type taught by the above noted patents have been highly effective for constructing grain bins which would have been considered large ten years ago, more recent, very large bin and tank structures are beginning to test the limits of what can be practically done with telescoping jacks of the type taught by the above referenced patents. A new type of jack is needed which can accommodate significantly larger loads and which is highly versatile for lifting a wide range of loads.